Dead chicks

i just got 8 more chicks last Friday and when I went out to check on them, two of them were dead. Two of them, that haven't died, act kind of strange. They show little interest in the food and sleep a lot. What's wrong with them

They came from Sal's Ol' Timey Feed & Seed. It's a big deck box, I'd say about 5 feet long and 2 feet wide. It's very tall and the heat lamp covers about half the Bonita the right height where it's not cold but not blazing hot. I put a broken half of a cinder block in there for them after I washed it off with a hose with a nozzle. I got starter feed from Sal's Ol' Timey Feed & Seed. It's locally made and is near the water. I change the water daily and I use big cedar shavings from Tractor Supply.